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From the technological perspective a portal is a dynamic Web page that consists of pluggable modules, called portlets. These portlets run in a portlet container. The container performs basic functionalities such as management of system resources and authenticating users, while portlets generate the actual Web interface. Portal developers realized that reusability of portlets is a key to the customizability of portals, and the interoperability of portlets across different container platforms in an important step towards this. Around 2001 the Java Specification Request (JSR) 168 emerged as a standard that allows portal developers, administrators and consumers to integrate standards-based portals and portlets across a variety of portal containers. Most of current science gateways are built from JSR-168 compliant portlets and provide easily customizable and reusable solutions for various purposes.

Grid portal examples

The usefulness of Grid portal technologies for computational science has been established by the number of portals being developed in Europe, the United States and Asia. In Europe the most relevant portal developer consortiums have gathered around the Enabling Grids for E-sciencE project (EGEE) and its national Grid counterparts. Some of these portals provide tools that are independent from scientific disciplines, others emphasize solutions that specific communities are familiar with and can utilize efficiently.

P-GRADE Portal provides facilities to create and execute computational simulations on cluster based Grids. Various user communities of the EGEE Grid and several European national Grids apply P-GRADE Portal as a graphical front-end to manage workflow applications on their infrastructures. While P-GRADE Portal is primarily a generic environment, it can be customized to any scientific domain by generating application specific portals from it that grants access only to pre-defined, domain specific workflows and simulations.

The NGS Applications Repository is an open access portal used to describe and list applications and their associated artefacts that are available on the National Grid Service (NGS) of the UK. Applications hosted by the repository are described using middleware agnostic documents, which can be searched for by categories of interest. The repository currently holds over 50 applications from various fields such as bioinformatics, engineering, chemistry, astrophysics or image analysis.

Outlook

The concept of content aggregation seems to still gain momentum and portal solution will likely continue to evolve significantly over the next few years. The Gartner Group recently predicted to expand on the Business Mashups concept of delivering a variety of information, tools, applications and access points through a single mechanism. Mashups are Web applications that combine data or functionality from two or more sources into a single integrated application. The term mashup implies easy, fast integration, frequently done by access to open programming interfaces and data sources to produce results that were not the original reason for producing the raw source data. An example of a mashup is the use of cartographic data from Google Maps to add location information to real estate data, thereby creating a new and distinct Web service that was not originally provided by either source.

Programmers of Grid and high performance computing portals still often find it hard to bridge between user friendly Web interfaces and low-level services of Grid middleware. Errors and faults sent back from the Grid are often difficult to interpret and deal with automatically, meanwhile it is inevitable that easy to use and autonomous portals are important tools to attract larger user communities to Grids. Grid portals will definitely improve in the near future in this respect.

References

  • M. Thomas, J Burruss, L Cinquini, G Fox, D. Gannon, I. Glilbert, G. von Laszewski, K. Jackson, D. Middleton, R. Moore, M. Pierce, B. Plale, A. Rajasekar, R. Regno, E. Roberts, D. Schissel, A. Seth, and W. Schroeder. Grid Portal Architectures for Scientific Applications. Journal of Physics, 16, pp 596-600. 2005.
  • “Web portal” entry in Wikipedia: (External Link) , last accessed 06/06/2009
  • Enabling Grids for E-sciencE project (EGEE): (External Link)
  • P. Kacsuk and G. Sipos: Multi-Grid, Multi-User Workflows in the P-GRADE Portal Journal of Grid Computing, Vol. 3, No. 3-4, Springer Publishers, pp. 221-238, 2005.
  • NGS Job Submission Portal: (External Link) , last accessed: 06/06/2009
  • “Mashup” entry in Wikipedia: (External Link) , last accessed 06/06/2009

Questions & Answers

differentiate between demand and supply giving examples
Lambiv Reply
differentiated between demand and supply using examples
Lambiv
what is labour ?
Lambiv
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WARKISA
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Lambiv
multiple choice question
Aster Reply
appreciation
Eliyee
explain perfect market
Lindiwe Reply
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
What is ceteris paribus?
Shukri Reply
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
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Shukri
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Shukri
what is monopoly mean?
Habtamu Reply
What is different between quantity demand and demand?
Shukri Reply
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
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Shukri
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what is the difference between economic growth and development
Fiker Reply
Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
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Jabir
What do you think is more important to focus on when considering inequality ?
Abdisa Reply
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Awais Reply
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
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In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
Feyisa Reply
Answer
Feyisa
c
Jabir
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
Gsbwnw Reply
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
types of unemployment
Yomi Reply
What is the difference between perfect competition and monopolistic competition?
Mohammed
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Source:  OpenStax, Research in a connected world. OpenStax CNX. Nov 22, 2009 Download for free at http://cnx.org/content/col10677/1.12
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